1. Field of the Invention
The present invention relates to a magnetoresistive effect device including a magnetoresistive effect element.
2. Description of the Related Art
The speed of wireless communication has increased in recent years with the increasing functions of mobile communication terminals, such as mobile phones. Since the communication speed is proportional to the band width of frequencies that are used, the number of frequency bands necessary for communication is increased. Accordingly, the number of high-frequency filters that are mounted in mobile communication terminals is increased. Spintronics has been studied in recent years as a field that is probably applicable to new high-frequency components. One phenomenon that has received attention is ferromagnetic resonance phenomenon caused by a magnetoresistive effect element (refer to Journal of Applied Physics 99, 08N503, 17 Nov. 17 2006). Application of an alternating-current magnetic field to a ferromagnetic film of the magnetoresistive effect element causes ferromagnetic resonance in magnetization of the ferromagnetic film, and the magnetization of the ferromagnetic film greatly oscillates at frequencies near a ferromagnetic resonance frequency. The ferromagnetic resonance frequency of the ferromagnetic film is generally within a high-frequency band from several gigahertz to several tens of gigahertz.